Automatic injection system

ABSTRACT

An automatic injection device is provided, where the device includes a syringe carrier and a retraction assembly. The syringe carrier includes two identical parts that are discrete from one another and interlock with one another. The retraction assembly includes a shuttle and a follower, the follower having a moveable latch. The follower has a coupled configuration in which the latch is biasedly coupled to the shuttle, and a decoupled configuration in which the latch is in sliding engagement with a curvilinear surface of the shuttle.

BACKGROUND

Aspects herein pertain to pharmaceutical injection devices, and, inparticular, to automatic injection devices.

Patients suffering from a number of different diseases frequently mustinject themselves with pharmaceuticals. A variety of devices have beenproposed to facilitate these injections. One type of device is anautomatic injection device. This type of device typically includes atrigger assembly that when operated by a user causes the device toautomatically insert into the user a needle of a syringe that prior totriggering was disposed within the device housing, and then the deviceautomatically injects a dose of medication through that inserted needle.The device may then automatically retract the syringe back into thedevice housing.

Some automatic injection devices include a syringe carrier that engageswith a flange of a syringe. The syringe carrier may only support theflange or, in some cases, move the syringe between retracted anddeployed positions. Some syringe carriers are of a single-piececonstruction. Some syringe carriers only partially surround the syringe,e.g. 270 degrees around the syringe, to leave an opening through whichthe syringe can be inserted radially.

Some automatic injection devices include retraction assemblies forauto-retraction of the syringe/needle combination. Retraction assembliesmay include two components that slidably engage with one another. Forexample, to retract the syringe, one component rotatably slides againstthe other component. The inventors have recognized that such slidingcontact can generate friction and/or friction variation along thesliding contact surfaces that may serve to impede retraction.Improvements to the syringe carrier and the retraction assemblies aredescribed herein.

SUMMARY

In some embodiments, an automatic injection device includes a housinghaving a proximal end and a distal end, and a syringe including aneedle, a syringe body and a plunger. The syringe is moveable within thehousing from a first position to a second position that is distal to thefirst position to move the needle toward distal proximal end of thehousing. The plunger is moveable relative to the syringe body to expelmedication from the syringe body through the needle. The automaticinjection device also includes a syringe carrier including two partsthat are identical to one another, are discrete from one another, andare interlocked together. Each of the two parts has a proximal flangesurface, a distal flange surface, a circumferential rounded wall betweenthe proximal flange surface and the distal flange surface. A gap islocated between the proximal flange surface, the distal flange surface,and the circumferential wall. A portion of the syringe body is receivedwithin the gap.

In another embodiment, an automatic injection device includes a housing,a syringe, and a syringe carrier. The housing includes a proximal endand a distal end. The syringe includes a needle, a syringe body and aplunger. The syringe body includes a syringe flange extending radiallyfrom the syringe body, and the plunger is moveable relative to thesyringe body to expel medication from the syringe body through theneedle. The syringe carrier includes a first part and a second part thatare discrete from one another, and are interlockable together. Each ofthe first and second parts includes a proximal flange surface, a distalflange surface, a circumferential rounded wall extending between theproximal flange surface and the distal flange surface, a cushiondisposed along a distal flange surface. The proximal flange surface andthe distal flange surface having a greater material hardness than thecushion. A gap is defined by the proximal flange surface, the cushion,and the circumferential rounded wall, receiving a portion of the syringeflange. The cushions of each of the first and second parts togetherdefining a ring shape to provide full circumferential support along thesyringe flange.

In some embodiments, an automatic injection device includes a housinghaving a proximal end and a distal end, and a syringe including aneedle, a syringe body and a plunger. The syringe is moveable within thehousing from a first position to a second position that is distal to thefirst position to move the needle toward the distal end of the housing.The plunger is moveable relative to the syringe body to expel medicationfrom the syringe body through the needle. The automatic injection devicealso includes a shuttle having a distal surface including a protrusionand a curvilinear surface. The curvilinear surface extends from theprotrusion to define an undercut region. At least a portion of thedistal surface is made of a lubricant-infused material. The automaticinjection device also includes a follower having a follower body and alatch. The latch is moveable relative to the follower body and relativeto the protrusion of the shuttle. The follower has a coupledconfiguration in which the latch is biasedly coupled over theprotrusion. The follower also has a decoupled configuration in which thelatch has cleared the protrusion and is in sliding engagement with thecurvilinear surface, the follower is rotatable relative to the shuttle,and the shuttle is moveable toward the proximal end of the housing toretract the syringe.

These and other aspects will be apparent from the following descriptionand claims.

BRIEF DESCRIPTION OF DRAWINGS

Aspects of the invention are described below with reference to thefollowing drawings in which like numerals reference like elements, andwherein:

FIG. 1 is a side view of an automatic injection device with a triggerassembly of according to one embodiment, which device is shown in alocked arrangement prior to use;

FIG. 2 is a longitudinal cross-sectional view of the automatic injectiondevice of FIG. 1 with the overcap removed;

FIG. 3 is a perspective view of a button shown separate from the othercomponents of the device of FIG. 1;

FIGS. 4a, 4b are respectively a perspective view and a partial side viewof a plunger element shown separate from the other device components;

FIG. 5a is an assembly including a syringe, syringe carrier, and plungerelement, with the syringe shown in phantom;

FIG. 5b is the assembly of FIG. 5a with one part of the syringe carrierhidden from view and the syringe shown in solid;

FIG. 5c is an enlarged view of a portion of FIG. 5 b;

FIG. 6a is a perspective view of a syringe carrier separate from theother device components;

FIG. 6b is an exploded perspective view of the syringe carrier of FIG. 6a;

FIGS. 7a, 7b, 7c, 7d, 7e and 7f are respectively top right perspective,bottom right perspective, top, bottom, front, and rear views of one partof the syringe carrier of FIG. 6 a;

FIG. 8 is a perspective view of another embodiment of a syringe carriermated with a syringe, with one part of the syringe carrier hidden fromview;

FIG. 9a is a perspective view of the part of the syringe carrier of FIG.8;

FIG. 9b is another perspective view of the part of the syringe carrierof FIG. 8;

FIG. 10 is a perspective view of a proximal shuttle part shown separatefrom the other device components;

FIGS. 11a, 11b, 11c, 11d and 11e are respectively perspective, firstside, longitudinal cross-sectional, top and bottom views of a distalshuttle part shown separate from the other device components;

FIGS. 12a, 12b, 12c, 12d and 12e are respectively first perspective,first side, second perspective, second side and longitudinalcross-sectional views of a follower shown separate from the other devicecomponents;

FIG. 13a is an assembly including a distal shuttle and a follower, thefollower being shown in the coupled configuration;

FIG. 13b is a slightly rotated view of the assembly of FIG. 13b to showthe interaction between a latch of the follower with a protrusion of thedistal shuttle;

FIG. 14 is an exploded view of the assembly of FIG. 13 a;

FIG. 15a is a perspective view of a distal shuttle;

FIG. 15b is another perspective view of the distal shuttle of FIG. 15 a;

FIGS. 16a and 16b are respectively perspective and side views of agrease collar shown separate from the other device components;

FIG. 17 is a longitudinal cross-sectional view of the automaticinjection device in its ready to operate arrangement;

FIG. 18 is a longitudinal cross-sectional view of the automaticinjection device after the automatic injection device has been triggeredfor injection.

DETAILED DESCRIPTION

Referring now to FIGS. 1 and 2, there are shown different views of afirst embodiment of an automatic injection device, generally designated20, with a trigger assembly. When the trigger assembly is operated, theneedled syringe of the device 20 is automatically driven downward suchthat the injection needle projects beyond the distal end of the devicehousing to penetrate the user. The device may then proceed to injectautomatically, that is without further user action, the medicationcontents of the syringe through the needle, after which the syringe isretracted automatically such that the needle is returned to within thehousing.

It will be appreciated from the following description that device 20 isconceptually similar in various aspects to the devices disclosed in U.S.Pat. No. 8,734,394, filed Feb. 24, 2011, and U.S. Pat. No. 9,872,961,filed Oct. 11, 2013, the disclosures of which are incorporated byreference herein in their entireties.

In the illustrative embodiment shown in FIG. 1, device 20 includes anouter housing 22 in which are operationally disposed working componentsof the device. The outer housing 22 may include a sleeve 26 and a mainbody 24 that may together form the axial height of the outer housing.Sleeve 26 may be rotatable relative to the main body 24 by the user. Thesleeve may include a protruding fin 93 to facilitate rotation by a user.The device may include a button 25 that is part of the trigger assemblyand that protrudes in the axial direction from the proximal end 27 ofthe housing. In some embodiments, when properly rotationally oriented byrotation of sleeve 26, the button 25 is unlocked such that the buttoncan be depressed in the distal direction to start the automaticinjection function of device 20. As used herein, distal and proximalrefer to axial locations relative to an injection site when the deviceis oriented for use at such site, whereby, for example, distal end ofthe housing refers to the housing end that is closest to such injectionsite.

Button 25 may be molded as a single piece from a suitably durablematerial, such as Lustran ABS 348. As further shown in the illustrativeembodiment of FIG. 3, button 25 may include a disc 35 with a skirt 37extending distally from the outer periphery of disc 35. End disc 35 mayhave a flat proximal face 38 upon which a force can be directly appliedby a user to selectively plunge the button to trigger the device. Anotch 40 may be formed in skirt 37 at the distal end of the skirt 37,and may extend axially and form a slot which receives a rib of sleeve 26so as to rotatably key together the button 25 and sleeve 26. A set ofthree equally angularly spaced resilient fingers 42 that may each beprovided with a detent on its radially inward face may be provided atthe base of skirt 37 for locating the button 25 on shuttle 200. Eachfinger 42 may be adjacent to one of three equally angularly spacedfingers 46 with inwardly angled stops 48 also provided in skirt 37 forattachment to shuttle 200.

Tapered flange portion 52 may have a sloped surface that serves as anactuating element of the trigger which cams a prong of the trigger tounlatch it for the trigger assembly. Differently designed actuatingelements, including one that is not ramp shaped, can be used to cam andthereby unlatch the prong in alternate embodiments.

In some embodiments, device 20 includes a medication-filled syringe. Asshown in FIG. 2, the syringe, generally designated 130, includes abarrel 132 with a flange 133, and an injection needle 134 mounted at thedistal end of the barrel and in fluid communication with the medicationcontents of the barrel. Although needle 134 is shown as a single needleand is generally expected to be sized for subcutaneous delivery, withadaptions the device could be equipped with a needle of various sizes ortypes known in the art, including, but not limited to, a needle formedof one or more shortened injection needles, including microneedlearrays, and which needle allows for injection at different depths, suchas intradermal.

Device 20 in general, and more particularly the technology claimed inthis application, may be utilized in injecting a variety of medicationsor therapeutics into a person in need thereof. Syringes of the devicesor claimed technology can be filled with any of a number oftherapeutics. Device 20 may further comprise a medication, such as forexample, within a reservoir within barrel 132 of syringe body orcartridge. In another embodiment, a system may comprise one or moredevices including device and a medication. The term “medication” refersto one or more therapeutic agents including but not limited to insulins,insulin analogs such as insulin lispro or insulin glargine, insulinderivatives, GLP-1 receptor agonists such as dulaglutide or liraglutide, glucagon, glucagon analogs, glucagon derivatives, gastric inhibitorypolypeptide (GIP), GIP analogs, GIP derivatives, oxyntomodulin analogs,oxyntomodulin derivatives, therapeutic antibodies, such as, for example,but not limited to treatment of psoriasis, ulcerative colitis, Chrohn'sdisease, pain, migraine, and any therapeutic agent that is capable ofdelivery by the above device. The medication as used in the device maybe formulated with one or more excipients. The device is operated in amanner generally as described above by a patient, caregiver orhealthcare professional to deliver medication to a person. The device,or claimed technology of this application, may then be operated in amanner generally as described above with respect to device 20 to injecta person with such therapeutic in the syringe.

The plunger mechanism may include a plunger element, generallydesignated 136, and an elastomeric sealing member or piston 138 thatseals the medication within barrel 132.

Plunger element 136 may be molded as a single piece of a lightweight butsturdy and sufficiently resilient material, such as DELRIN 311DP fromDupont Engineering Polymers. As further shown in FIG. 4a , plungerelement 136 includes a cylindrical foot 140 which may be hollowed so asto have a cruciform center 142. The distal face 144 of foot 140operationally abuts piston 138 during plunger advancement. A ribbed bar146 may rigidly or inflexibly extend axially upward from the top of foot140 to a disc-shaped flange 150 that has a larger diameter than foot140. A plunger arm 152 may be formed on the outer radial periphery offlange 150 and may extend axially and distally from flange 150 in spacedrelationship with plunger bar 146.

Four equally angularly spaced bosses 153 may upwardly project from theflange 150. Bosses 153 may aid in centering the drive coil spring 155shown in FIG. 2 that acts on flange 150 to bias plunger element 136distally within device 20.

Plunger element 136 may include a resilient prong, generally designated160, that serves as part of the trigger assembly. The single prong 160may latchably engage a shuttle in the shown embodiment until released bythe plunging of button 25, which release allows the spring 155 to biasthe plunger element 136 distally to result in needle insertion andinjection. In some embodiments, the plunger includes one and only oneresilient prong. In other embodiments, however, the plunger may includemore than one resilient prong.

Prong 160 may include an upstanding, tapering finger 162 that projectsaxially from the center of flange 150 so as to be centered on the axisof the housing 22. Finger 162 may be flexible due to its construction toallow its bending movement when the prong is acted on for its release.As shown in FIG. 4b , prong 160 may include a triangular projection 165centered on the side to side width of finger 162. Projection 165 mayinclude a ramp surface 167 extending proximally and at an angle inwardfrom the tip 169 of the projection 165 to form an outward facing rampused in camming of the prong for release. Ramp surface 167 extends fromtip 169 to a proximal end 168. The distal face 170 of projection 165,which face does not serve a latching function, is transverse to theaxial direction.

A pair of latching surfaces 172 may be provided on the proximal-mostportions 171 of extensions 174 of finger 162. Latching surfaces 172 andextensions 174 flank either side of projection 165 and are spacedradially inward from the ramp surface 167 at the height of the latchingsurfaces along prong 160. Latching surfaces 172 are provided generallyin axial alignment with finger 162 and each may be formed with a slightundercut so as to slope slightly distally as it extends in the radialdirection toward ramp surface 167. Latching surfaces 172 are disposed ata height between the axial extent of ramp surface 167, such as near theproximal end 168. In this location, the contacting forces on the rampsurface may tend to produce a translational deflection of the latchingelement which may have a lower and more consistent unlatching force thanwould a rocking or pivoting motion, caused by the latching surfacesbeing substantially above or below the ramp surface, that wouldintroduce extra deformation of prong 160 and make the unlatching motionless smooth.

The back surface of projection 165 may jut rearward beyond extensions174 to define a safety protuberance 178. Protuberance may be backed upby safety arm 72 when button 25 is in its locked orientation.

An assembly including the plunger element 136, syringe carrier 185, andsyringe 130 is shown in FIG. 5a . The plunger bar 146 of the plungerelement 136 extends through an opening 158 in the syringe carrier 185and into the syringe carrier. As shown in FIGS. 5b and 5c , in which onepart of the syringe carrier is hidden from view, the syringe carrierencloses a radial flange 133 of the syringe 130. As also seen in FIGS.5b and 5c , the syringe carrier also encloses the foot 140 of theplunger element. The syringe carrier 185 may be configured to providefull, surrounding support of the syringe flange 133 of syringe 130.While such syringe carrier may be desired, designs of the syringecarrier which allow for manufacturing and assembly is also desirable inhigh-volume manufacturing settings.

An illustrative embodiment of a fully assembled syringe carrier is shownin FIG. 6a . The syringe carrier may be made up of a first part 156 thatcouples with a second part 157. The parts 156, 157 may be coupled to oneanother by various attachment mechanisms, such as, for example,adhesives, such as bonding glue, ultrasonic welding, mechanicalinterlocking, and the like. An exploded view of the syringe carrier isshown in FIG. 6b . The two halves of the syringe carrier combine todefine a cavity 450 that receives syringe flange 133 during deviceassembly such that the syringe carrier 185 surrounds the flange 133.

In some embodiments, the syringe carrier 185 is made up of twoidentical, interlocking parts. One embodiment of one of the parts isshown in FIG. 7a . The part shown in FIG. 7a is the first part 156 ofthe syringe carrier, but the second part 157 may also be identical towhat is shown in FIGS. 7a -7 f. Having the first and second parts beidentical may have the benefit of requiring manufacture of only oneshape, and may facilitate assembly of the syringe carrier by avoidingthe need for a particular part being oriented at a specific side of thesyringe carrier. Other embodiments of the parts having at least some ofthe features described herein may include parts that are not identicaland still provide interlocking and support to the flange.

The first part 156 may include a proximal flange surface 402, a distalflange surface 404, and a circumferential rounded wall 410 disposedbetween the proximal flange surface 402 and the distal flange surface404. An axial gap 460 is defined between the proximal flange surface 402and the distal flange surface 404. The gap 460 is sized to receive theaxial thickness of flange 133 (see FIG. 5c ) of the syringe. Theproximal flange surface 402 may include a proximal flange extending fromthe wall, and the distal flange surface 404 may include a distal flangeextending from the wall in parallel with the proximal flange.

In some embodiments, the syringe carrier 185 may include a cushion 187that defines a distal boundary for the gap 460. With reference to FIG.5c , the distal surface of flange 133 of the syringe may rest againstand be supported by the proximal surface 187A of cushion 187 when theflange is held by the syringe carrier. In some embodiments, the rest ofthe syringe carrier is made of a material having a greater hardness thanthat of cushion 187. The cushion 187 may provide shock absorbance orother impact attenuation to, e.g., reduce the likelihood of breakage ofthe syringe during actuation of the automatic injection device, and/orto soften the impact sound of the syringe against the syringe carrierduring movement of the syringe. The cushion may be made by overmolding amaterial onto the syringe carrier. The cushion may be formed of acompressible material, such as an elastomer or a closed cell foam.

In some embodiments, the cushion may be arc-shaped to fit with the shapeof the circumferential rounded wall 410 and/or the shape of the distalflange surface 404. In some embodiments, the cushion 187 segments areconfigured and shaped, such as in a ring shape, to provide fullcircumferential, that is 360 degrees, support to the entire flange 133when the parts 156, 157 are coupled. To this end, in some embodiments,the parts are shaped around the flange so that the cushion 187 canprovide this full support to the flange 133, such as, for example, towithstand spring insertion drive forces.

In some embodiments, the syringe carrier 185 may include one or moreprotrusions extending radially inward, where the protrusions mayfacilitate centering of the syringe within the syringe carrier bycontacting the syringe body underneath the syringe flange. In theembodiment shown in FIG. 7a , the syringe carrier includes a protrusion188 that extends from an inner radial surface 189 of the cushion 187.The protrusion may be made from the same cushioning material as thecushion 187 and may be integrally formed with the cushion 187 as asingle component. The protrusions may be radially compressed to agreater degree relative to any radial compression of the surface 189 bythe syringe body. In the embodiment shown, the cushion 187 of each ofthe parts includes a pair of protrusions 188 a and 188 b (as shown inFIG. 7d ) so that when the parts are coupled to one another theprotrusions together help centering of the syringe at four points. Inone example, the coupled parts define the four protrusions that arearranged spaced equally apart from one another. When parts are coupled,the number of protrusions provided can vary between two or more. Inanother embodiment, the one or more protrusions may optionally includethe protrusion 191 that can be located along the inner radial surface189 in closer proximity to a latch protrusion 430 than a prong 420, andin some embodiments, adjacent to the end of the inner radial surface 189next to the latch protrusion as shown in FIG. 7a . In other embodiments,there may be a protrusion adjacent the end of the inner radial surface189 next to the prong 420 in addition to, or instead of, the protrusion191. Protrusion 191 may be included to support the syringe during thesnap engagement of the two parts of the syringe carrier together, whenthe portion of the part 156 or 157, which includes the latch protrusions430, flexes radially outward when mating with the prongs 420 of theother part. After the snap engagement, the protrusion 191 may alsoprovide additional support to the syringe at a location where when matedthere may be a gap between the cushions.

The proximal flange surface 402 may provide supportive engagement forthe proximal surface of foot 140 of the plunger element.

Each part of the syringe carrier may define an opening portion 45defined by radial plunger facing walls that forms one part of theopening 158 of the fully assembled syringe carrier. Such opening portion45 may be shaped and sized to receive the shape and size of the plungerelement in a manner to provide sliding support to the plunger body. Inthe example shown, the opening portion 45 in each part has a U-shapewith opposing parallel planar sides coupled to one another by a roundedside.

The edges 405, 407 of the proximal flange surface of one of the parts ofthe syringe carrier disposed lateral relative to the opening portion 45may be complementarily shaped to mate with the edges of the other of theparts, such as shown in FIG. 6a . The edges may have a planar shape. Inthe embodiment shown, each of the edges is non-linearly shaped includinga protrusion and recess.

In some embodiments, each part of the syringe carrier 185 may include afirst lateral wall end 411 and a second lateral wall end 412, where thecircumferential rounded wall 410 extends from the first lateral wall end411 to the second lateral wall end. In the embodiment shown, the firstlateral wall 411 is disposed recessed relative to the edge 407, whilethe second lateral wall 412 is disposed protruding relative to the edge405.

The syringe carrier 185 may include interlocking components thatinterlock to form the fully assembled syringe carrier. In someembodiments, the interlocking components extend from the lateral wallends of each part of the syringe carrier. In the embodiment shown inFIGS. 7a and 7b , the interlocking components comprise prongs 420, eachhaving an indentation 421, and latch protrusions 430, each having anaccompanying slot 432. The prongs 420 may extend from one of the lateralwalls, shown as the first lateral wall end 411, and the protrusions 430extend from the other of the lateral walls, shown as the second lateralwall end 412. Each of the prong 420 and indentation 421 of the firstpart 156 of the syringe carrier are complementarily shaped and sized tomate with a corresponding protrusion 430 and slot 432 of the second part157 of the syringe carrier to interlock the two parts of the syringecarrier together.

As seen from the top view in FIG. 7c and the bottom view in FIG. 7d ,each part of the syringe carrier may be approximately C-shaped. As seenfrom the front view in FIG. 7e and the front view in FIG. 7f , thesyringe carrier may include a window 490 that passes completely throughthe circumferential rounded wall 410 of the syringe carrier.

As best seen in FIG. 5a , the syringe carrier 185 may fully surround anouter perimeter of the syringe body, i.e. 360 degrees around the syringebody. The proximal and distal flange surfaces 402, 404 of each of theparts together fully overlap the proximal surface 133A and/or the distalsurface 133B of the syringe flange 133, as shown in FIG. 5a . Thisconfiguration of a syringe carrier completely surrounding and/oroverlapping the syringe flange may be advantageous when higher springforces for driving the plunger are used by the delivery device, such as,for example, due to larger volume of medication, such as 2 to 3 mL,and/or higher viscous medications. Such configuration can allow fordistribution of the drive force over a greater area of the syringeflange, which may help to reduce the likelihood of breakage of thesyringe flange that are typically made of glass.

It should be understood, however, that other configurations for thesyringe carrier are possible. One alternative embodiment is shown inFIG. 8. In FIG. 8, one part of the syringe carrier 185′ is removed tobetter see the flange 133′ of the syringe interacting with the syringecarrier. The proximal flange surface 402′ and the distal flange surface404′of both parts of the syringe carrier 185′ together may be configuredto provide full 360 degree support to the syringe flange 133′. Thesyringe carrier may also include the cushion 440, shown disposed alongthe proximal surface of the distal flange surface 404′. When employed,the flange 133′ would rest along the cushion in a position in betweenthe cushion and the proximal flange surface 402′.

As seen in FIGS. 9a -9 b, in this embodiment, the syringe carrier 185′has a wall 410′ that does not extend laterally side to side as far asthe embodiment shown in FIG. 7a . This shortened wall 410′, relative tothe longer circumferential extension of the proximal and distal flangesurfaces 402′, 404′, allows for lateral spaces 495, 496 flanking thelateral ends of the wall 410′. In some embodiments, these spaces 495,496 may be used to accommodate syringes having flanges with differentshapes, such as the cut flange syringe shown in FIG. 8.

The syringe carrier may have interlocking components in the form ofprotrusions 425 and indentations 426. The protrusions 425 of the firstpart of the syringe carrier interlock with the indentations 426 of thesecond part. These interlocking components may have other snap-fitconfigurations. Due to the shortened wall 410′, the interlockingfeatures are shown defined by the respective flange surfaces 402′, 404′.Indeed, the protrusions 425 and indentations 426 are shown defined bythe radially inward edges 405′, 407′ of the corresponding flangesurfaces 402′ 404′. In one embodiment, the circumferential rounded wall410′ partially surrounds an outer perimeter of the syringe flange 133′,and the proximal flange surface 402′of each of the parts together fullyoverlap a proximal surface 133A′ of the syringe flange 133′. As shown inFIG. 8, the distal flange surface 404′ of each of the parts togetherfully overlap the proximal surface 133B′ of the syringe flange 133′,with the cushion 440 disposed therebetween.

Device 20 may have a delay mechanism that includes a shuttle, generallydesignated 200, a follower 250 that releasably latches with the shuttle200, and a dual functioning biasing member 275 acting between theshuttle and the follower. Shuttle 200 may be formed of a proximalshuttle 202 and a distal shuttle 204 further shown in FIG. 10 and FIGS.11a -11 e, respectively, that are fixedly connected during manufacturingassembly. The interaction between the proximal shuttle 202 and thedistal shuttle 204, as well as the features of the proximal shuttle 202are described in greater detail in U.S. Pat. No. 9,872,961.

Distal shuttle 204 includes distal region 270, and the flange 272 thattransitions from body 210 to region 270 is designed to engage syringecarrier 185. When the distal shuttle 204 is moved proximally duringretraction, the flange 272 abuts against a distal surface of the syringecarrier 185, thus moving the syringe carrier 185 and syringe barrel 132in the proximal direction with proximal movement of the distal shuttle204. Groove 280 in distal shuttle body 210 receives a housing key torotatably fix shuttle 200 with a cavity in sleeve 26. In someembodiments, the device includes a different drive system, where thesyringe carrier 185 and syringe barrel may remain stationary (that is,is not proximally moved), and where the syringe carrier still provides abenefit to the syringe flange.

Tabs 282 and 284 radially project from distal region 270 and serve aslatching elements or hooks to engage the follower. Notch 286 that leadsto pocket 288 within tab 282 receives a proximal projection 289 of thebiasing member 275.

An angled, locking latch surface 290 is disposed distally of an opening292 in line with an axially extending channel 294 formed in the interiorsurface of distal shuttle body 210. Channel 294 accommodates plunger arm152 that can project through opening 292 to unlock the locking mechanismdescribed below.

Follower 250 is further shown in FIGS. 12a-12e and includes a proximalportion 298 with ledges 300 and 302 that serve as latching elements thatengage shuttle latching tabs 282 and 284. Channel 304 and opening 306 inproximal portion 298 allow axial movement of tabs 282 and 284 thereinfor manufacturing assembly and for shuttle release relative to thefollower during device use. Opening 306 tapers to a slot-shaped portion310 adapted to closely receive a radial projection 312 of biasing member275.

A radially projecting flange 316 may snap past snaps in the main body 24during device assembly. The interior surface of follower portion 298includes an inwardly projecting ring 318 with a spring centering lip320. A sleeve shaped distal portion 322 of follower 250 depends fromfollower portion 298 and has a lesser diameter. Slots 324 in the distaledge of portion 322 define four damping fins 326 of the follower. Theslots 324 can be adjusted in size to create to differing delay times. Alocking member for follower 250 to limit its rotation relative to theshuttle 200 is formed as a flexure arm 330 with an upwardly extendinglatch 332 at its end.

An exploded view of the distal shuttle 204, biasing member 275, andfollower 250 is shown in FIG. 14. Biasing member 275 may function asboth a torsion spring and a compression spring, with torsionalpreloading and an axial preloading accomplished during the manufacturingassembly of device 20. Biasing member 275 is shown as a cylindricalspring formed of a helically coiled wire 311, with a shuttle engagingtip in the form of a proximal projection 289, and a follow engaging tip312.

An assembly of the distal shuttle 204 and follower 250 shown in acoupled configuration is shown in FIGS. 13a and 13b . In the coupledconfiguration, the latch 332 of the follower is engaged with aprotrusion 213 on a distal surface 211 of the distal shuttle 204.

As shown in FIGS. 15a and 15b , the distal surface 211 of the distalshuttle 204 has an undercut region 215 adjacent to the protrusion 213.The undercut region 215 has a curvilinear shape. In some embodiments,the trailing surface 335 may be curved and the undercut region 215 maybe curvilinear to facilitate sliding engagement between both.

As shown in FIG. 12d , the latch 332 of the follower is axially moveablerelative to the follower body 251 due to cantilevered flexure arm 330,which is able to deflect relative to the follower body. The latch 332may be comprised of a leading surface 333 and a trailing surface 335.The sliding contact between the latch surfaces and the shuttle duringrotation of the follower relative to the shuttle can generate frictionvariability that impede consistent rotation speed of the follower. Theleading surface 333 engages with the protrusion 213 when the follower isin the coupled configuration in FIG. 13b . The trailing surface 335 mayslidingly engage with the undercut region 215 when the follower is in anuncoupled configuration and is rotating relative to the distal shuttle204. In the uncoupled configuration, the latch 332 is disengaged withthe protrusion 213. In some embodiments, the leading surface 333 may bea flat surface that engages in a confronting relationship a flat surfaceportion 214 of the protrusion 213. At least one, or both, of the leadingsurface 333 and flat surface portion 214, may be angled slightly tofacilitate latching with and/or uncoupling from the protrusion 213. Insome embodiments, the trailing surface 335 may be curved to facilitateuncoupling of the latch from the protrusion, and/or facilitate slidingengagement with the undercut region 215.

Distal shuttle 204 may include a lubricant-infused material to aide inthe movement of the distal shuttle 204 within the device housing,particularly during the needle retraction operation. In one example, theentire distal shuttle includes lubricant-infused material. In someembodiments, at least the distal surface 211 of the distal shuttle ismade of a lubricant-infused material. Such a material may aid infacilitating uncoupling of the latch 332 from the protrusion 213 and/orfacilitating sliding engagement between the latch 332 and the undercutregion 215 as the follower 250 rotates relative to the distal shuttle.In some embodiments, the lubricant-infused material may serve todecrease friction and/or friction variability between the distal shuttleand the latch during movement of the follower relative to the distalshuttle. The lubricant-infused material may also serve to lower frictionand/or friction variability between the tabs 282, 284 with the ledges300, 302. In some embodiments, the material may be a silicone-infusedmaterial. In some embodiments, the material may be made of polycarbonatewith infused silicone of 2%. In some embodiments, all of or at least aportion of the follower 250 may be made of a copolymer to decreasefriction and/or friction variability between the distal shuttle and thefollower. In some embodiments, at least one of at least the distalsurface 211 of the distal shuttle is made of a lubricant-infusedmaterial, the trailing surface 335 may be curved, the undercut region215 may be curvilinear, copolymer follower, or any combination thereofmay be employed to provide a retraction assembly for an automaticinjection device which can facilitate syringe retraction by decreasingthe sliding engagement friction and/or by decreasing friction variationthat is generated during retraction. Such embodiments may reduce anyfrictional delay variability in rotational speed and timing of thefollower to a position to allow for shuttle/syringe retraction and/orand more consistent retraction speed and timing at the completion of thedelivery cycle, which together may avoid factors contributing to stalledretraction.

The device may include a grease collar 340, further shown in FIGS. 16aand 16b , that provides a support surface for damping fluid as thefollower 250 rotates relative to that support surface. Collar 340includes an annular body 342 through which fits the syringe barrel.Collar 340 is axially supported within the housing 22. Collar body 342includes a generally U-shaped wall that defines an annular hollow 346.

A damping compound 350 (shown in FIG. 2), such as a silicone greasethickened with Teflon, may fill annular hollow 346. Follower fins 326fit within hollow 346 such that compound 350 is disposed both radiallyinward and outward of such fins 326, as well as between adjacent fins326 and as a film between the fin undersides and the base of the collarwall, resulting in a damping or delay effect as the follower fins 326try to rotate relative to the collar.

The construction of device 20 will be further understood in view of adescription of one illustrative embodiment of its operation after theend cap is removed in preparation for an injection. To arrange device 20to inject, sleeve 26, and thereby button 25, is manually rotated by auser to an unlocked state in which the device is ready to inject.

A cross-sectional view of the device in the unlocked state is shown inFIG. 17. When a user subsequently applies a distal force on button 25,button 25 starts to move downward into sleeve 26, thereby driving flangesurface 54 against ramp surface 167. As button 25 continues to movefurther distally, with flange portion 52 inserting further into theshuttle opening, flange surface 54 slides along ramp surface 167. Duringthis sliding, flange portion 52 cams prong 160 radially outward becauseflange portion 52 is prevented from bending in the opposite radiallyoutward direction due to the contact with the supportive collar surface234. Flange portion 52 is prevented from twisting due to contact withsupportive surfaces on the proximal shuttle 202. Prong 160 can be cammedoutward as finger 162 bends until latching surfaces 172 disengage fromlatch surfaces on the proximal shuttle, at which point the proximal-mostportion of plunger prong 160 passes downward through the shuttle due tospring 155 directly biasing the plunger element 136 downward to drivethe plunger element and thereby the piston 138 distally, which drivenmotion shifts syringe barrel 132 and syringe carrier 185 distallyrelative to the shuttle and the housing to cause the tip of needle 134to project beyond the housing distal end for penetrating a user's skin,and then forces the medication contents of the syringe through thatneedle for an injection.

As plunger element 136 moves distally during medication injection, thearm 152 abuts against the latch 332 of the follower 250, causing flexurearm 330 to deflect distally, causing the leading surface 333 of thelatch to slide distally past the protrusion 213 of the distal shuttle204, thus causing the latch 332 to clear the protrusion 213. With thelatch 332 disengaged from the protrusion 213 of the distal shuttle 204,the follower 250 is in the uncoupled configuration, and the follower 250is thus unlocked for rotation relative to the distal shuttle 204. FIG.18 shows the arrangement of device 20 at this point of the use process.

Follower 250, as urged by the torsional preloading of biasing member275, rotates against the damping effect of damping compound 350, duringwhich rotation remaining medication can be properly expelled from thesyringe through the needle. When follower 250 has rotated such thatshuttle tabs 282 and 284 are clear of ledges 300 and 302, shuttle 200and follower 250 are thereby unlatched so as to allow the compressivelypreloaded biasing member 275 to decompress, forcing shuttle 200proximally to retract the syringe carrier 185 and the syringe barrel 132along with the syringe carrier, thereby retracting the distal tip of theinjection needle 134 to a protected, retracted position within thehousing 22.

While the automatic injection device described herein has been shown anddescribed as having preferred designs, the present device may bemodified within the spirit and scope of this disclosure. For example,while the biased element that the trigger assembly releases in the shownembodiment is the plunger that itself contacts the syringe piston, thetrigger assembly could be used to release different biased elements inalternate embodiments, or elements that are biased with parts differentthan coiled springs. This application is therefore intended to cover anyvariations, uses or adaptations of the device using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this automatic injection device pertains.

Having thus described several aspects of at least one embodiment of thisinvention, it is to be appreciated various alterations, modifications,and improvements will readily occur to those skilled in the art. Suchalterations, modifications, and improvements are intended to be part ofthis disclosure, and are intended to be within the spirit and scope ofthe invention. Accordingly, the foregoing description and drawings areby way of example only.

Various aspects are described in this disclosure, which include, but arenot limited to, the following aspects:

1. An automatic injection device, including: a housing including aproximal end and a distal end; a syringe including a needle, a syringebody and a plunger, the syringe being moveable within the housing from afirst position to a second position that is distal to the first positionto move the needle toward the distal end of the housing, and the plungerbeing moveable relative to the syringe body to expel medication from thesyringe body through the needle; a syringe carrier including a firstpart and a second part that are identical to one another, are discretefrom one another, and are interlocked together, each of the first andsecond parts including: a proximal flange surface; a distal flangesurface; a circumferential rounded wall between the proximal flangesurface and the distal flange surface; and a gap located between theproximal flange surface, the distal flange surface and thecircumferential rounded wall, wherein a portion of the syringe body isreceived within the gap.

2. The automatic injection device of aspect 1, wherein each of the firstand second parts of the syringe carrier includes a protruding prong thatinterlocks with the other of the first and second parts.

3. The automatic injection device of any one of aspects 1-2, wherein thesyringe carrier includes a cushion, the proximal flange surface and thedistal flange surface having a greater material hardness than thecushion.

4. The automatic injection device of aspect 3, wherein the syringe bodyincludes a syringe body flange, and the cushion is in contact with thesyringe body flange.

5. The automatic injection device of aspect 3, wherein the cushionincludes at least one radial protrusion extending from an inner radialsurface of the cushion.

6. The automatic injection device of any one of aspects 1-5, wherein thesyringe body includes a syringe body flange, wherein the circumferentialrounded wall of the syringe carrier partially surrounds an outerperimeter of the syringe flange, and the proximal flange surface of eachof the parts together fully overlap a proximal surface of the syringeflange.

7. The automatic injection device of any one of aspects 1-6, wherein thesyringe body includes a syringe body flange, wherein the proximal flangesurface of each of the parts together fully overlap a proximal surfaceof the syringe flange.

8. The automatic injection device of any one of aspects 1-7, wherein thesyringe carrier fully surrounds an outer perimeter of the syringe body.

9. The automatic injection device of any one of aspects 1-8, whereineach of the first and second parts of the syringe carrier includes afirst lateral wall end and a second lateral wall end, thecircumferential rounded wall extending from the first lateral wall endto the second lateral wall end, the first lateral wall end having aprong, and the second lateral wall end having a latch protrusion,wherein the prong of the first part of the syringe carrier interlockswith the latch protrusion of the second part of the syringe carrier.

10. An automatic injection device, including: a housing including aproximal end and a distal end; a syringe including a needle, a syringebody and a plunger, the syringe body including a syringe flangeextending radially from the syringe body, and the plunger being moveablerelative to the syringe body to expel medication from the syringe bodythrough the needle; a syringe carrier including a first part and asecond part that are discrete from one another, and are interlockedtogether, each of the first and second parts including: a proximalflange surface; a distal flange surface; a circumferential rounded wallextending between the proximal flange surface and the distal flangesurface; a cushion disposed along a distal flange surface, the proximalflange surface and the distal flange surface having a greater materialhardness than the cushion; and a gap defined by the proximal flangesurface, the cushion, and the circumferential rounded wall, receiving aportion of the syringe flange, wherein the cushions of each of the firstand second parts together defining a ring shape to provide fullcircumferential support along the syringe flange.

11. The automatic injection device of aspect 10, wherein the cushionincludes at least one protrusion contacting the syringe body underneaththe syringe flange, flange, wherein the at least one protrusion isdisposed adjacent to an end of an inner radial surface of the cushion ofeach of the first and second parts.

12. The automatic injection device of any one of aspects 10-11, whereinthe first part and the second part are identical to one another, each ofthe first and second parts having interlocking elements configured tocouple to one another, and walls defining together an openingsurrounding the moveable plunger.

13. An automatic injection device, including: a housing including aproximal end and a distal end; a syringe including a needle, a syringebody and a plunger, the syringe being moveable within the housing from afirst position to a second position that is distal to the first positionto move the needle toward the distal end of the housing, and the plungerbeing moveable relative to the syringe body to expel medication from thesyringe body through the needle; a shuttle having a distal surfaceincluding a protrusion and a curvilinear surface, the curvilinearsurface extending from the protrusion to define an undercut region, atleast a portion of the distal surface being made of a lubricant-infusedmaterial; and a follower having a follower body and a latch, the latchbeing moveable relative to the follower body and relative to theprotrusion of the shuttle; wherein: the follower has a coupledconfiguration in which the latch is biasedly coupled over theprotrusion, and the follower has a decoupled configuration in which thelatch has cleared the protrusion and is in sliding engagement with thecurvilinear surface, the follower is rotatable relative to the shuttle,and the shuttle is moveable toward the proximal end of the housing toretract the syringe.

14. The automatic injection device of aspect 13, wherein the latchincludes a cantilevered arm with an end having a protrusion.

15. The automatic injection device of aspect 14, wherein the protrusionhas a straight leading surface and a curved trailing surface, whereinthe straight leading surface is in contact with the protrusion when thefollower is in the coupled configuration, and the curved trailingsurface is in contact with the curvilinear surface when the follower isin the decoupled configuration.

16. The automatic injection device of any one of aspects 13-15, whereinthe lubricant-infused material includes silicone.

17. The automatic injection device of any one of aspects 13-16, whereinthe entire shuttle is made of the lubricant-infused material.

18. The automatic injection device of any one of aspects 13-17, furtherincluding a spring that is compressed between the shuttle and thefollower when the follower is in the coupled configuration.

19. The automatic injection device of aspect 18, wherein the spring istorsionally pre-loaded when the follower is in the coupledconfiguration.

20. The automatic injection device of any one of aspects 13-19, whereinthe shuttle is moveable toward the proximal end of the housing after thefollower has rotated through a predetermined angle of rotation.

21. The automatic injection device of aspects 1, 11 or 13, wherein thesyringe body contains a medication.

22. The automatic injection device of aspects 1 and 11 may be combinedtogether alone, or along with any other aspects described herein.

What is claimed is:
 1. An automatic injection device, comprising: a housing comprising a proximal end and a distal end; a syringe including a needle, a syringe body and a plunger, the syringe being moveable within the housing from a first position to a second position that is distal to the first position to move the needle toward the distal end of the housing, and the plunger being moveable relative to the syringe body to expel medication from the syringe body through the needle; a shuttle having a distal surface comprising a shuttle protrusion and a curvilinear surface, the curvilinear surface extending from the shuttle protrusion to define an undercut region, at least a portion of the distal surface being made of a lubricant-infused material; and a follower having a follower body and a latch, the latch having a cantilevered arm being moveable relative to the follower body and relative to the shuttle protrusion, the cantilevered arm with an end having a latch protrusion, wherein the latch protrusion has a straight leading surface and a curved trailing surface; wherein: the follower has a coupled configuration in which the latch is biasedly coupled over the shuttle protrusion and the straight leading surface of the latch protrusion is in contact with the shuttle protrusion, and the follower has a decoupled configuration in which the latch has cleared the shuttle protrusion and the curved trailing surface of the latch protrusion is in sliding engagement with the curvilinear surface, the follower is rotatable relative to the shuttle, and the shuttle is moveable toward the proximal end of the housing to retract the syringe.
 2. The automatic injection device of claim 1, wherein the lubricant-infused material comprises silicone.
 3. The automatic injection device of claim 1, wherein the entire shuttle is made of the lubricant-infused material.
 4. The automatic injection device of claim 1, further comprising a spring that is compressed between the shuttle and the follower when the follower is in the coupled configuration.
 5. The automatic injection device of claim 4, wherein the spring is torsionally pre-loaded when the follower is in the coupled configuration.
 6. The automatic injection device of claim 1, wherein the shuttle is moveable toward the proximal end of the housing after the follower has rotated through a predetermined angle of rotation.
 7. The automatic injection device of claim 1, wherein the syringe body contains a medication.
 8. The automatic injection device of claim 1, further comprising a syringe carrier including a first part and a second part that are discrete from one another and interlocked together, each of the first and second parts comprising a proximal flange surface, a distal flange surface, a circumferential rounded wall between the proximal flange surface and the distal flange surface, and a gap located between the proximal flange surface, the distal flange surface and the circumferential rounded wall, wherein a portion of the syringe body is received within the gap, wherein the shuttle is engageable with the syringe carrier during proximal movement.
 9. The automatic injection device of claim 8, wherein the syringe carrier includes a cushion, the proximal flange surface and the distal flange surface having a greater material hardness than the cushion.
 10. The automatic injection device of claim 9, wherein the syringe body includes a syringe body flange, and the cushion is in contact with the syringe body flange.
 11. The automatic injection device of claim 10, wherein the cushion includes at least one cushion protrusion contacting the syringe body underneath the syringe body flange, wherein the at least one cushion protrusion is disposed adjacent to an end of an inner radial surface of the cushion of each of the first and second parts.
 12. The automatic injection device of claim 8, wherein the syringe body includes a syringe body flange, wherein the circumferential rounded wall of the syringe carrier partially surrounds an outer perimeter of the syringe body flange, and said proximal flange surface of each of the parts together fully overlap a proximal surface of the syringe body flange.
 13. An automatic injection device, comprising: a housing comprising a proximal end and a distal end; a syringe including a needle, a syringe body and a plunger, the syringe being axially moveable within the housing from a first position to a second position that is distal to the first position to move the needle toward the distal end of the housing, and the plunger being axially moveable relative to the syringe body to expel medication from the syringe body through the needle; a shuttle coupled to the syringe, the shuttle having a distal surface comprising a shuttle protrusion and a curvilinear surface, the curvilinear surface extending from the shuttle protrusion to define an undercut region; and a follower having a follower body and a latch, the latch being moveable relative to the follower body and relative to the shuttle protrusion, the latch comprising a latch protrusion, the latch protrusion having a straight leading surface and a curved trailing surface; wherein: the follower has a coupled configuration in which the latch of the follower is biasedly coupled with the shuttle protrusion to inhibit rotation of the follower, the straight leading surface of the latch protrusion is in contact with the shuttle protrusion, and the follower has a decoupled configuration in which the latch protrusion has cleared the shuttle protrusion and the curved trailing surface of the latch protrusion is in sliding engagement with the curvilinear surface of the shuttle as the follower is rotated relative to the shuttle, the shuttle axially moveable toward the proximal end of the housing to retract the syringe after the follower has rotated through a predetermined angle of rotation.
 14. The automatic injection device of claim 13, wherein the distal surface of the shuttle is made of a lubricant-infused material.
 15. The automatic injection device of claim 13, further comprising a syringe carrier including a first part and a second part that are discrete from one another and interlocked together, each of the first and second parts comprising a proximal flange surface, a distal flange surface, a circumferential rounded wall between the proximal flange surface and the distal flange surface, and a gap located between the proximal flange surface, the distal flange surface and the circumferential rounded wall, wherein the syringe body comprises a syringe flange that is received within the gap, wherein the shuttle is engaged with the syringe carrier during proximal movement when the syringe being retracted.
 16. The automatic injection device of claim 15, wherein the syringe carrier includes a cushion, the proximal flange surface and the distal flange surface having a greater material hardness than the cushion, wherein the cushion is in contact with the syringe flange.
 17. The automatic injection device of claim 13, further comprising a spring that is compressed between the shuttle and the follower when the follower is in the coupled configuration.
 18. The automatic injection device of claim 17, wherein the spring is torsionally pre-loaded when the follower is in the coupled configuration, and the spring urges rotation of the follower relative to the shuttle when the follower is in the decoupled configuration.
 19. The automatic injection device of claim 13, wherein the syringe body contains a medication. 